No cancer left hidden
PROSTATE cancer is the most prevalent and second highest killer cancer in men globally. Consultant urologist at Subang Jaya Medical Centre Datuk Dr Tan Hui Meng says prostate cancer occurs in one in every nine men. This statistic increases to one in four in the case of men with a family history of prostate and breast cancer.
While some may think prostate cancer is more prevalent in western countries, Dr Tan says it is increasing in incidence in Asian society because of our changing ways of life, diet and genetics. “Prostate cancer is now the No.1 killer cancer in certain Asian countries, even though it is a slowmoving cancer.”
Very little to work with
Until the last three decades, the prostate specific-antigen (PSA) test was the only tool available to doctors to screen for prostate cancer. However, one major issue of the PSA test is that it only indicates the chances that one has prostate cancer instead of confirming that the patient has prostate cancer.
Dr Tan says, “It was a major controversy in the medical community as it was found that only 20% of men benefited from this test. Because of the PSA test’s inaccuracy, men were often misdiagnosed, over-diagnosed and over-treated. The subsequent prostatic biopsies (often done through the rectum/anus) and treatment following the test result also put men at risk of erectile dysfunction, incontinence, heart attack, sepsis and sometimes even death.”
Because of this, the United States Preventive Services Task Force, an independent panel of experts that systematically reviews clinical preventative services, urges that PSA tests are only performed when necessary. Now, doctors carry out “screening” in a more focused manner, where only men at risk are screened. It is also emphasised that the PSA test and the consequence following the test result should only be carried out as a shared decision between men and their urologists.
Towards better accuracy and outcomes
In the last six years, multiparametric magnetic resonance imaging (MPMRI) has changed the world of prostate cancer diagnosis for the medical community. Dr Tan explains that while PSA is still used to monitor a person’s risk of developing prostate cancer, prostate imaging with
MPMRI allows doctors to examine the prostate tissue in more detail to determine whether there is presence of an aggressive cancer. This way, more men are spared the experience of unnecessary biopsies, and more are saved with accurately diagnosed killer cancer.
Improvements for biopsies are also underway. In contrast with the usually performed transrectal ultrasound-guided biopsy, which accuracy is only 50%, doctors are now performing biopsies with MPMRI guidance usually through the perineum (avoiding the contaminated rectum/anus). “We fuse the MRI image with the ultrasound image. This way, we can determine the exact location of the lesions and take samples using a tiny needle through the perineal skin (area between the scrotum and anus) accordingly,” says Dr Tan.
Dr Tan has high hopes for the diagnosis and treatment of prostate cancer in the near future. “We will soon be incorporating genomic testing and focal therapy into prostate cancer prevention and treatment for low grade or intermediate grade cancer. Highgrade prostate cancers are usually ablated with surgery or radiotherapy. Genomic testing helps us determine who should be put on active surveillance, be repeat biopsied or have their prostate removed, while focal therapy allows us to remove cancerous growths in a minimally invasive way.”
All in all, he says prostate cancer is still life threatening and extremely prevalent in our ageing population. Therefore, he emphasises early detection of clinically important prostate cancer, and suggests PSA test for men older than 50 who have risk factors or are concerned of prostate cancer. “When you have a baseline PSA test done early on, we can determine if you are at risk of developing prostate cancer, and help you either keep it under control or treat you depending on the growth rate (aggressiveness) of the cancer.”
For more information, call 03-5639 1212.